Substrates such as glass and steel are used to make buildings, appliances, cars, etc. Oftentimes, it is necessary to apply a functional coating(s) over the substrate to achieve certain performance properties. Examples of functional coatings are electroconductive coatings, photocatalytic coatings, low emissivity coatings, hydrophilic coatings, hydrophobic coatings, anti-reflective coatings, etc.
Typically, the functional coating is deposited directly on the substrate. When the functional coating is deposited directly on the substrate, the coated substrate can fail to achieve the desired performance, have poor durability and exhibit undesirable aesthetic properties. For example, a functional coating applied directly on a substrate may fail to exhibit a desired performance such as a specified amount of photocatalytic activity or exhibit poor durability by peeling off or changing color. As another example, a functional coating deposited directly on a substrate may exhibit undesirable aesthetic properties such as increased reflectance and/or unwanted color.
The present invention provides a substrate coated with a novel undercoating and a functional coating that is applied over the undercoating. The coated substrate according to the present invention can exhibit improved performance properties such as aesthetic properties, durability, photocatalytic activity, mechanical durability, etc.